Acquisition of aerial imagery traces its history back to the Wright brothers, and is now commonly performed from satellite and space shuttle platforms, in addition to aircraft.
While the earliest aerial imagery relied on conventional film technology, a variety of electronic sensors are now more commonly used. Some collect image data corresponding to specific visible, UV or IR frequency spectra (e.g., the MultiSpectral Scanner and Thematic Mapper used by the Landsat satellites). Others use wide band sensors. Still others use radar or laser systems (sometimes stereo) to sense topological features in three dimensions. Other types of image collection rely on electro-optical panchromatic (grayscale), multi-spectral (less than 20 bands) and hyper-spectral (20 bands or more). Some satellites can even collect ribbon imagery (e.g., a raster-like, 1-dimensional terrestrial representation, which is pieced together with other such adjacent ribbons).
The quality of the imagery has also constantly improved. Some satellite systems are now capable of acquiring image and topological data having a resolution of less than a meter. Aircraft imagery, collected from lower altitudes, provides still greater resolution.
A huge quantity of aerial imagery is constantly being collected. Management and coordination of the resulting large data sets is a growing problem. Integrating the imagery with related information is also a problem.
In accordance with one embodiment, digital watermarking technology is employed to help manage such imagery and related information, among other benefits. In another embodiment, a digital watermark conveys information that is used to register or align geographic information system (GIS) layers with a corresponding image location, perhaps after the image has been distorted.
In accordance with yet another embodiment, a method of operating a network filter is provided. The network comprising a plurality of network nodes, the network filter for filtering video or audio. The method includes: monitoring video or audio traffic to a particular network node; identifying a first video or audio at the particular network node through deriving or extracting identifying data from data representing the first video or audio, the deriving or extracting utilizes at least one programmed multi-purpose computer processor; determining additional information associated with the first video or audio based at least in part on the identifying information; and notifying the network node of the presence of the additional information.
In accordance with still another embodiment, a method of scheduling an alert to announce the presence of available information associated with video or audio is provided. The method includes: receiving identifying data from a remotely located computer device, the remotely located computer device including at least one multi-purpose processor, wherein the identifying data is obtained through deriving or exacting attributes from data representing the video or audio with at least a multi-purpose processor; monitoring data records associated with the identifying data; and upon identifying updated information associated with the identifying data, sending a message or alert to the remotely located computer device announcing the availability of the updated information.
The foregoing and additional features and advantages of the present invention will be even more readily apparent from the following detailed description with reference to the following figures.